3121 results about "Femtosecond" patented technology

The present invention relates to the apparatus, system and method for dicing of semiconductor wafers using an ultrafast laser pulse of femtosecond and picosecond pulse widths directly from the ultrafast laser oscillator without an amplifier. Thin and ultrathin semiconductor wafers below 250 micrometer thickness, are diced using diode pumped, solid state mode locked ultrafast laser pulses from oscillator without amplification. The invention disclosed has means to avoid / reduce the cumulative heating effect and to avoid machine quality degrading in multi shot ablation. Also the disclosed invention provides means to change the polarization state of the laser beam to reduce the focused spot size, and improve the machining efficiency and quality. The disclosed invention provides a cost effective and stable system for high volume manufacturing applications. An ultrafast laser oscillator can be a called as femtosecond laser oscillator or a picosecond laser oscillator depending on the pulse width of the laser beam generated.

A sub-micron structure is fabricated in a transparent dielectric material by focusing femtosecond laser pulses into the dielectric to create a highly tapered modified zone with modified etch properties. The dielectric material is then selectively etched into the modified zone from the direction of the narrow end of the tapered zone so that as the selective etching proceeds longitudinally into the modified zone, the progressively increasing width of the modified zone compensates for lateral etching occurring closer to the narrow end so as to produce steep-walled holes. The unetched portion of the modified zone produced by translating the laser beam close to and parallel to the bottom surface of the dielectric can serve as an optical waveguide to collect light from or deliver light to the etched channel which can contain various biological, optical, or chemical materials for sensing applications.

Surface enhanced Raman Scattering (SERS) and related modalities offer greatly enhanced sensitivity and selectivity for detection of molecular species through the excitation of plasmon modes and their coupling to molecular vibrational modes. One of the chief obstacles to widespread application is the availability of suitable nanostructured materials that exhibit strong enhancement of Raman scattering, are inexpensive to fabricate, and are reproducible. I describe nanostructured surfaces for SERS and other photonic sensing that use semiconductor and metal surfaces fabricated using femtosecond laser processing. A noble metal film (e.g., silver or gold) is evaporated onto the resulting nanostructured surfaces for use as a substrate for SERS. These surfaces are inexpensive to produce and can have their statistical properties precisely tailored by varying the laser processing. Surfaces can be readily micropatterned and both stochastic and self-organized structures can be fabricated. This material has application to a variety of genomic, proteomic, and biosensing applications including label free applications including binding detection. Using this material, monolithic or arrayed substrates can be designed. Substrates for cell culture and microlabs incorporating microfluidics and electrochemical processing can be fabricated as well. Laser processing can be used to form channels in the substrate or a material sandwiched onto it in order to introduce reagents and drive chemical reactions. The substrate can be fabricated so application of an electric potential enables separation of materials by electrophoresis or electro-osmosis.